Secure conduit (pathway) system for telecommunications and communications transmission equipment, environmental analysis equipment, computer equipment and the like

ABSTRACT

A method comprises selecting a first elongated channel member with at least two open ends, placing an elongated carrier in the first channel member so that it extends through the at least two open ends, placing a first cover over an open side of the first channel member to form a hollow first conduit section in combination therewith so that the elongated carrier extends therethrough, and locking the first cover to the first channel member with a locking device that is operable only from within the first conduit section and is accessible only through an open end thereof.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on upon and claims benefit of the filing dateof U.S. Provisional Patent Application Ser. No. 60/480,726, filed onJun. 23, 2003. This application is also a continuation-in-part of U.S.patent application Ser. No. 10/690,272. filed on Oct. 21, 2003, of liketitle.

BACKGROUND OF THE INVENTION

1. Field of Invention

The invention relates generally to conduits, raceways and similardevices for routing signalling or transmission apparatus such as cables,tubing and wires (including those composed of either metal or opticalfiber) between locations. More particularly it relates to such deviceswhich must be used for signalling or transmission in a highly secureenvironment.

2. Background Information

In many industries, research facilities and governmental and militaryfacilities there is a need for secure routing of signaling andtransmission means such as computer, power, communication and similarcables and wires and fluid conveyance tubing, e.g., gas and liquidpneumatic and hydraulic lines. (For brevity herein such signalling andtransmission means will often be exemplified as and referred tocollectively as “cable”, “cables” or “cabling” unless the contextindicates otherwise or specific types of such means are mentioned. Itwill be recognized, however, that such collective terminology is usedfor convenience only and is not intended to be limiting.) Further, theterms “conduit” and “conduit system” may be considered synonymous unlessthe context indicates otherwise.) Unauthorized access to such cablesmust be prevented or at least made extremely difficult while yet easy todetect. Conduits for routing of such cables must be protected fromintrusion by penetration or removal of access covers or sections ofconduit, and also must provide a suitable degree of physical protectionfor the transmission devices within the conduit from environmentalhazards, weather and climate excesses and accident or attack. However,such protection must not be so cumbersome that authorized access forremoval, repair or insertion of the cables within the conduit is madeexcessively difficult.

Typical uses for the present secure conduit invention will be forcomputer networks, communication systems, equipment control systems,remote sensing systems and the like. Specific principal uses which maybe illustrated as examples are as conduits for telecommunicationscables, computer cables, power transmission cables (especially for powerto critical operational equipment or facilities) and environmental gassampler tubing or piping. Users may be companies, researchorganizations, military units and governmental organizations andagencies. Facilities where secure conduits are desirable include officeand laboratory buildings; military camps and bases; ships, dockyards orother marine facilities; airports; prisons; chemical plants andpetroleum refineries; factories; banks, exchanges and other financialinstitutions; and power, gas and water utilities.

In the past, there have been numerous cable and other routing systems,such as those used to route computer, electric power and communicationscables and wires to and within offices, especially within a building. Aparticularly successful example of such a system is that described andclaimed in U.S. Pat. No. 5,831,211, owned by the assignee of the presentinvention and patent application, Holocom Networks of Carlsbad, Calif.,and commercially available under the trademark TOPRUNNER®. A principallimitation of such systems, however, is that they are not secure fromintrusion and cannot be made secure without extensive modification. Suchmodification is impractical in most cases, since the intent of theirdesigners and their users has been to have them readily accessible tofacilitate frequent reconfiguration. Therefore while such non-securesystems do provide functions similar to those of the system of thepresent invention, i.e., routing of cables, their physical structuresand security capabilities are entirely different.

It would therefore be of significant value to have a secure conduitsystem which would provide security against unauthorized access tocables routed through the system, while at the same time permittingsimple and easy access to those cables within the system to authorizedpersons.

SUMMARY OF THE INVENTION

The invention described and claimed herein is of apparatus for securerouting of signalling or transmission means which comprises anopen-sided open-ended elongated channel member through which the meansis routed, a cover for closure of the open side of the channel member, alocking device to lock the cover to the channel member or enclosures,the locking device being releasable only from within the channel member;and release means for releasing the locking device and accessible thoughan open end of the channel member, whereby the cover and the channelmember, once locked together, can be separated only by release of thelocking device by access through an open end of the conduit, pathway orenclosure. Normally there will be plurality of channel members alignedend-to-end, each with its own cover. For most of the channel members,the covers will be held on by simple locking tabs which engageprojections or ribs within the channel members. After assembly of thelatter cover/channel pairs, the remaining cover and channel member willbe assembled with the locking device to secure the entire length of theconduit. The conduit preferably terminates at its ends in secureenclosures which limit access to the interior of the conduit to onlythat which can be gained through the enclosures. Other secure enclosuresmay be spaced along the length of the conduit.

T-, Y-, L- and X-shaped and other curved, bent, or multibranchedraceway/cover pairs can be included in the conduit structure to formbranches which allow conduit directional changes, junctions and multipleconduit routes. In such cases each conduit branch should terminate in aseparate secure enclosure, and normally a cover/channel pair with alocking device will be included in each branch, unless the branch isquite short, such that it can be secured by abutting the main securedportion of the conduit.

The signalling or transmission means of significance in this inventionincludes, but is not limited to, computer, power, communication andsimilar cables and wires and fluid conveyance tubing, e.g., gas andliquid pneumatic and hydraulic lines. Within the secure conduit of thisinvention any one or more of such means may be routed, the number beinglimited primarily by the physical size of the conduit and by thesharpness of any turns in the conduit. Where a conduit has multiplebranches, individual cables may follow different paths through theconduit system, such that different numbers of cables may be present indifferent branches of the system.

The locking device which permits securing of the cover to the conduitmay be secured within the conduit in a variety of manners, such as byuse of spring-urged pins engaging projecting ribs on the interior wallsof the conduit or by use of bolts which allow clamping of the lockingdevice to both the top of the conduit and to the interior ribs.

Details of the invention and further descriptions will be found below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a typical conduit assembly mounted on a wall ofother supporting surface;

FIG. 2 is a perspective view of a flange connector;

FIG. 3 is an enlarged sectional view taken on line 3—3 of FIG. 1;

FIG. 4 is a perspective view from above of a locking unit;

FIG. 5 is a perspective view from below of the locking unit of FIG. 4;

FIG. 6 is a perspective view of a section of a raceway;

FIG. 7 is a perspective view of a section of a top cover;

FIG. 8 is a perspective view of a lock connector;

FIG. 9 is an end view of the lock connector of FIG. 8 with the lockingtab secured in place;

FIG. 10 is a perspective view of a snap-in connector;

FIG. 11 is an end view of the connector or FIG. 10 with the snap springsecured in place;

FIG. 12 is an enlarged sectional view taken on line 12—12 of FIG. 6showing the initial insertion of a locking unit;

FIG. 13 is a view similar to FIG. 12 showing the locking unit secured inplace;

FIG. 14 is an enlarged sectional view taken on line 14—14 of FIG. 3;

FIG. 15 is a view similar to FIG. 13 illustrating an alternativeembodiment;

FIG. 16 is an enlarged sectional view taken on line 16—16 of FIG. 1;

FIG. 17 is an enlarged sectional view taken on line 17—17 of FIG. 16;

FIG. 18 is a perspective view of a corner raceway component;

FIG. 19 is a perspective view from below of a corner top cover;

FIG. 20 is a top view of a T-shaped junction unit;

FIG. 21 is a schematic view from above of a mechanized system forlocking and unlocking the locking unit;

FIG. 22 is a perspective view from above of yet another alternativeversion of the locking unit of FIG. 4 illustrating a different structurefor securing the locking unit in place;

FIG. 23 is a perspective view from above of an alternative version ofthe locking unit of FIG. 4;

FIG. 24 is a perspective view of above of another alternative version ofthe locking unit of FIG. 4;

FIGS. 25 and 26 are respectively perspective views from below of thelocking unit of FIG. 24 in an unlocked and locked configuration,illustrating locking and unlocking by spring pins and a U-shaped springrelease;

FIGS. 27, 28 and 29 are perspective separated views of the two halves ofrespectively a T-shaped locking junction unit, an X-shaped lockingjunction unit and an L-shaped locking corner unit;

FIG. 30 is a plan view from below of the interior of an L-shaped bendunit, similar to the L-shaped corner unit of FIG. 29;

FIGS. 31 and 32 are oblique views of one end of alternative embodimentof raceways of FIG. 6 formed respectively from aluminum and steel

FIGS. 33 and 34 are, respectively, an oblique and an exploded obliqueview of an alternative embodiment to the release mechanism of FIGS. 25and 26;

FIG. 35 is an oblique view from below of a top cover illustrating analternative means of locking the top cover in place;

FIG. 36 is an end view of an assembled raceway, top cover and lockingmechanism of FIGS. 34–36, with the locking rod removed for clarity;

FIGS. 37 and 38 are, respectively, an oblique and an exploded obliqueview of an alternative lanyard embodiment to the spring releasemechanism of FIGS. 29 and 30 for corner (L-shaped) and angled sections;

FIGS. 39 and 40 are respectively an oblique and top view (with the topcover removed) of a large radius T-junction section of conduit,illustrating a release mechanism equivalent to that of FIGS. 37 and 38;

FIG. 41 is an oblique view similar to that of FIG. 39 but illustratingan embodiment where locking release is by spring mechanism rather thanby lanyard release; and

FIG. 42 is an elevation view, partially in cross-section and cut away,illustrating a structure for connection between two secure systemsthrough a barrier wall.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS

For the purposes of this invention, the terms “secure”, “secureconduit”, “secure conduit system”, “secure enclosure” and the like areintended to include those systems which meet the requirements of“Protective Distribution Systems (PDS)” as defined by the NationalSecurity Telecommunications and Information Systems Security Secretariatof the National Security Agency in Instruction No. 7003 (NSTISSI 7003:issued 13 Dec. 1996), the content of which is incorporated herein byreference. In addition to those secure conduit systems which are“secure” within the meaning of the PDS requirement, the presentinvention may also be used for secure conduit systems where the degreeof security is not within the specific PDS standard. Such other conduitsystems may include various non-governmental and/or commercial systemsto which NSTISSI 7003 may not be applicable or where application isvoluntary.

It will also be recognized that security of a conduit system is often afunction of both the system's resistance to penetration or entry and theease of an observer's being readily able to tell that penetration orentry has been attempted or accomplished. Thus as will be described theconduits of the present invention are commonly installed with stand-offsor other means to isolate the conduits from contact with adjacentsurfaces, such that an observed can by sight or touch readily examineall exterior sides of conduit components to detect any attempt atpenetration of or entry into the system. Thus where inspection of asystem is frequent or the sections of the system are readily in view ofobservers, such that attempts at penetration or entry will be easilyseen, the conduit components themselves for such sections may be formedof materials which are themselves less resistant to penetration thatwould be called for in sections of the conduit where inspection is lessfrequent or more difficult to accomplish.

The invention described and claimed herein is a secure conduit systemthrough which electrical, electronic or optical fiber cables, pneumatictubing, hydraulic tubing or other elongated wiring, cabling or tubingcan be routed. The conduit system can be connected at its various endsto secure enclosures which allow for secure controlled access to thecabling inside the conduit system. Typical uses will be for computernetworks, communication systems, power transmission, equipment controlsystems, remote sensing systems and the like. Principal uses which maybe illustrated as examples in electrical, electronic andtelecommunications fields include secure routing of power cables,computer cables and communications cables for networked computer systemsand wired telecommunications systems. Locations may be within, betweenor outside buildings. The secure conduit system will also be ofimportance even with wireless communications systems, such as forsecurity of landline cabling from the generating or receiving equipmentto the sending/receiving antennas.

Another example of potential users' systems is a system for remoteenvironmental air, gas or liquid sampling and analysis. In this type ofsystem, a fluid-tight tube, hose or pipe is run from a storage oranalysis location to a remote sampling site where the pipe terminates inan open liquid-, air- or gas-sampling device. Periodically orcontinually samples of the environment at the sampler point are taken,and then transported back through the pipe to a collection system foranalysis or directly to an analysis system. Such secured pipe is desiredwhen the liquid, gas or air in the pipe cannot be leaked to the outsideor accessed by unauthorized persons or in an unauthorized manner. Suchunauthorized access is of particular concern when the liquid, gas or airbeing sampled is itself flammable, toxic or otherwise dangerous, or whenit may be contaminated with or otherwise carry or entrain flammable,toxic or otherwise dangerous components.

It is not intended that the secure conduit itself normally be air-,liquid- or gas-tight, although its closed configuration is such that itcan be exposed to inclement environments and will to some extent resistinfiltration of rain, snowmelt, blown dust and similar commonenvironmental elements. Should greater environmental protection bedesired, it is contemplated that the cabling can be encased in aprotective sleeve or similar device prior to being installed within theconduit, or alternatively the conduit itself, after insertion of thecables can be encased in such a protective covering. It will berecognized that reconfiguring of the conduit contents will thereafternormally necessitate removal of some or all of the protective covering.

It will be understood that reference to an embodiment as “alternative”is intended to indicate only that the present invention includes anumber of variations of the various embodiments as to structure,materials of construction, number and types of conduit components, andthe like. All are considered to be substantially equivalent in overallperformance. A user of the invention can readily select the specificcombinations of components, materials, etc. which are best suited forthe particular location, environment and specified security requirementsfor the particular system which he or she needs. Numerous examples willbe referred to below.

The invention is best understood by reference to the Figures of thedrawings. FIG. 1 shows the components of the secure conduit system 2 ina very simplified installation and a wall 4. Installations will commonlybe mounted on walls, ceilings, space dividers, bulkheads, buildingstructural members such as columns, rafters, studs and joists, and othersimilar supports. They may also span short unsupported spaces (usuallynot more than 3–10 ft [about 1–3 m]) such as running across spaced-apartjoists or studs. The raceway may be surface mounted, but for the mostsecurity, however, and as required for PDS installations, most or all ofthe secure conduit will not be surface mounted, but rather will bemounted spaced apart from the surface over which it runs, so stand-offsare needed along the conduit to maintain it in position. Thisrequirement is to insure that observers of the conduit can detect anyattempts to penetrate the conduit from its back side, by being able tosee any suspicious hole in the surface to which it is mounted or anysuspicious device bridging the gap between the surface and the conduit.Over the length of a conduit run, different means of attachment,stand-off and support may be used at different locations.

Prior to installation, one first determines the locations of the varioussecure enclosures 6 needed along the secure conduit 2 and the desiredroute of the conduit (including branches thereof) to reach thoseenclosures. It is not necessary that the route selected be the shortestpossible. As noted, there are a number of different uses for the secureconduit which are anticipated to result in different numbers of secureenclosures along the route, with different spacings between adjacentenclosures. Secure enclosures 6 have been produced and sold commerciallyby the assignee of this patent application and are also the subject ofcopending U.S. utility patent application Ser. No. 10/112,353, alsoassigned to the assignee of this application. Essentially each suchsecure enclosures 6 incorporates a box-like structure which houses aconnection to apparatus of a secure signalling or transmission system 2such as a computer network, communications network or environmentalanalysis system. To attach to or gain access to the secure system 2, auser must have a device (e.g., a computer) external to the enclosure butwhich can be connected to the system 2. The enclosure 6 is normallyclosed by a penetration-resistant door, which if desired may have a backflange to further enhance penetration resistance and which is locked bya secure lock. (Where the system is one which meets the PDSrequirements, the lock itself will meet corresponding governmentalrequirements.) An authorized user will have a key or combination to thelock and can open the door and access a connection device on the securesystem 2 apparatus within the enclosure. The user then makes theconnection with his/her device and proceeds to do whatever is desiredduring access to the secure system. For instance, a computer user couldaccess a secure database or give operating commands to a piece ofequipment which is operated via the secure system or a chemist couldtake samples of the fluid passing through an environmental samplingtube. Security of the enclosure is assured since the user must keep thedoor open while having access, so an observer can see the user at work.Normally only a single connection is provided inside each enclosure, soonly a single individual can access the system at a time through theenclosure. Further, if the user terminates his/her use of the system butdoes not close the enclosure after use, that also is observable sincethe door can be seen to be open and the identity of the user as theperson who last accessed the enclosure will be known. While FIG. 1 showssecure enclosures 6 at each end of the conduit 2, it will be recognizedthat additional secure enclosures may be positioned at points along thelength of the conduit 2, such that access may be had to intermediatesections of the contained cables. Thus, for instance, multiple computeraccess enclosures may be present on a single computer network cable sothat multiple computer users can access the computer network, eachthrough his or her individual access enclosure.

It is also possible to interconnect two physically separate securesystems of this invention. FIG. 42 illustrates such a connection throughtwo secure enclosures 6 and 6′ mounted on opposite sides of a barrierwall 230. Corresponding holes 232 and 232′ are drilled through the backof each enclosure 6, 6′ and through the wall 230 and a short strong pipeor elongated nipple 234, threaded on both ends, is passed through theholes and extended into the interior of each enclosure 6, 6′, where itis secured by conventional nuts and washers 236, 236′ covering theannular portions of the holes 232, 232′, so that external access to thepipe 234 is prevented. Wires, cables, and pneumatic conduits from asecure system 2 of this invention can then be routed through the pipe234 to a second secure system 2′ of this invention without compromisingthe integrity and security of either system.

The secure conduit system 2 connects to a secure enclosure 6 by means ofa flange connector 8, as shown in FIGS. 2 and 3. The wall 10 ofenclosure 6 has an aperture 12 (usually circular) through which thecircular end extension 14 of the flange connector 8 is inserted.Extension 14 has external threads 16 which are disposed within theenclosure 6 upon insertion and the connector 8 is secured to theenclosure wall 10 by threading circular nut 18 onto threads 16 untilflange 20 of connector 8 abuts the exterior side of wall 10. Extendingfrom flange 20 is connector tube 22 which is hollow with a cross-section(usually square or rectangular) which corresponds similar to thecross-section of the raceway 26 and cover 28. An aperture 24 in flange20 provides passage for cables from within the enclosure 6 into theconnector tube 22 and thus into the conduit system.

A principal component of the system 2 is at least one, and usually many,raceways 26. A raceway 26 can be any convenient length. It is convenientto provide stocks of raceway 26 in several standard lengths, for example1, 3, 6 and 10 feet (or metric counterparts of 30 cm and 1, 2 and 3 m).These can be cut to shorter lengths as needed and joined to make longerlengths. Covering the raceways over most of their length are at leastone (and also usually many) top covers 28. As best shown in FIGS. 3, 6,31 and 32, a raceway 26 is an elongated channel member having agenerally U-shaped cross-section with an open top 30 and suitable forthe routing of cables, wires, tubing and the like. (For purposes of thisinvention the word “raceway” includes all suitable elongated channelmembers, regardless of whether they may be referred to by other names inspecific industries.) The specific U-shaped cross-section is notcritical, as long as it can securely interfit with a corresponding topcover 28. The particular U-shaped cross-section will in many cases bedependent on the type of material from which the raceway 26 (and topcover 28) is made and how it is manufactured. For instance, aluminumraceways may be formed by extrusion, which allows for roundedconfigurations and internal ribs (see FIGS. 3, 6 and 31) while steelraceways commonly are formed by bending which results in morestraight-sided and sharper-edged embodiments (see FIG. 32). In theembodiment of FIGS. 3 and 6, the side walls 32 curve over inwardly atthe top to form protruding longitudinal flanges 34. Positioned on theinterior of the raceway 26 and disposed parallel to flanges 34 are apair of longitudinal ribs 36. In the FIG. 31 embodiment, the top potion34′ of flanges 34 is flattened with an inwardly folded end portion 34″,and the function of the ribs 36 is performed by the downwardly facingends 36′ of the folded end 34″, while in the FIG. 32 embodiment thestructure is generally V-shaped with top portion 34′ being rounded andthe end portions 43″ slope inwardly. The bottom of the raceway 26 isusually flat as shown in FIGS. 31 and 32, but may be stepped as shown at40 to accommodate a linking plate 42 which connects two racewaysabutting at their ends (FIG. 3). One half of a gap bridge 42 is securedto the inside of the bottom of the raceway 26 as by adhesive bonding orspot welding, and then the other half is similarly secured to theabutting raceway 26 to form a firm connection between the two raceways.For most of the raceway elements 26, a closed top cover 28 having acomplementary U-shaped cross section and no apertures (see FIG. 7) isused to close the open top 30 of the raceway 26 once the cabling hasbeen inserted. The closed top cover 28 has secured on the inside thereof(as by spot welding) a locking tab 38, which interfits with the ribs 36and locks the top cover 28 in place.

To start assembly of a secure conduit system 2 a flange connector 8 isfirst inserted into a secure enclosure 6 and fastened tightly asdescribed above. One end of a first raceway 26 is inserted fully intothe connector tube 22, butting up against the portion of flange 20 whichsurrounds aperture 24. In the embodiment illustrated in FIG. 3, a topcover 28 is then fitted over the raceway 26. This top cover 28 will havean aperture 88 in it as illustrated in FIG. 8, for cooperation with thelocking device 52 as will be described below. Connector tube 22 will besized to accommodate both raceway 26 and top cover 28, so that theleading end of top cover 28 will have its end also abut flange 22 andthe entire combination of the raceway 26 and the top cover 28 fill theinterior of connector tube 22. At least for the first section of theconduit, the top cover 28 is preferably longer than the raceway 26 sothat when the second raceway 26 is attached to the first raceway 26, thefirst top cover 28 will extend over the exposed end of the first raceway26 for a short distance to cover the joint between the two racewayelements. A gap bridge 42 will join the two raceways. Thereafter thesecond raceway 26 is capped with a top cover 28 which does not have anaperture 88. A locking tab 38 may be positioned in the second top cover28, as shown in FIGS. 10 and 11, to engage the ribs 36 in the secondraceway 26 to secure the second top cover 28. Alternatively, if desiredthe structure of FIGS. 10 and 11 may be a supplemental cover 85 whichcan be slip fitted to overlay two abutting top covers 28 and 28′ andextend into abutting raceways 26 and 26′ to lock the raceways and topcovers together through engagement of the tab 38 and thus blockpenetration or separation of the abutment joint 87, as illustrated inFIGS. 16 and 17. It will be seen that conduits of any desired length canbe constructed in this manner by sequential assembly of additionalraceways 26 and top covers 28, as desired, either joined directly bytabs 38 or indirectly by supplemental covers 85.

L-shaped corner or elbow raceways 46 (FIG. 18) their top covers 48 (FIG.19) and corresponding T-, Y- and X-shaped or other multi-armed branchingjunction raceway units and their corresponding top covers (generallyindicated at 50; FIG. 20) may be incorporated as needed to construct thedesired overall system configuration. Where larger diameter wires orcables are to be routed within the system 2 or where there are a largenumber of wires or cables within the conduit 2, it will be desirable touse broadened configurations of the L-, T-, X- and Y-shaped junctionunits such as illustrated in FIGS. 39, 40 and 41 at 51. The broadenedconfigurations allow for larger radius turns of the wires or cables andthus prevent kinking at turns. Some corners and other units may have theraceways and covers secured together by the locking mechanisms describedherein which incorporate internal and external elements as illustrated,e.g., in FIGS. 3 and 16. However, alternative configurations of suchunits with internal locking mechanisms are illustrated in FIGS. 27–30,38 and 40. In these alternative configurations the raceway 26 hassecured to the middle portion thereto (as by spot welding or strongadhesive) an upwardly extending bar 210 terminated by a barrel 212disposed parallel to the inner top surface of the top cover 28. Theinner top surface of the cover 28 has a corresponding latching member214 which is configured as one half of a hinge, with knuckles 216serving as guides for a sliding pin 218 (similar to a hinge pin) with ahooked end 220 to allow for manipulation of the pin 218. In one mode ofoperation when the raceway 26 and the cover 28 are interfitted, thebarrel 212 fits between two of the knuckles 216 a and 216 b with theirrespective axes aligned, and the pin 218 can be manually moved fromwithin the interior of the interfitted raceway/cover to a position whereit is extended through the barrel 212 and at least the knuckles 216 aand 216 b in the manner of a hinge pin to lock the raceway 26 and thecover 28 together. While the T-, Y- and X-configured units can operatewith only one bar 210/member 214 pair, the L-shaped corners or bends(elbows) will normally require two pairs, one in each leg of the L,unless the L is very shallow (i.e., the bend or elbow encompasses only asmall angle). One can optionally put additional pairs in two or morearms of the T-, Y- and X-shaped units to enhance their resistance tounauthorized access. One may also support the pin 218 within the barrel212 and have it slide into one or more of the knuckles 216 asillustrated in FIGS. 29 and 30. Other convenient configurations will beevident to those skilled in the art depending on the specific alignmentsof adjacent parts of the conduit bend, elbow, junction, etc. It willalso be evident that once locked together in this manner, the racewayand cover can only be unlocked for separation from within the conduit,thus enhancing secutiry and prevention of unauthorized access for thepresent system.

The system requires that at least one location a closed top cover willnot be used. Rather at this location a locking top cover (describedbelow) will be inserted once the insertion of the cabling is completedand the closed top covers have been placed. In the preferred assemblyprocedure, at least for a portion of the system the raceways 26 arefirst placed, including any corner or junction raceways in that portion.Preferably this section will be one which connects to a secureenclosure. The cabling is then laid into the raceways 26 through theopenings 30 in their tops and the ends of the cabled passed into theinterior of the enclosure. This installation of cabling by simply layingthem in the raceways will be recognized to be much easier than having tothread or fish the cables through closed conduits. It may also bedesired to lay the cabling throughout the entire conduit system at thistime, instead of laying the cabling only for one portion of the systemat a time, particularly if the system is fairly short (as for instancewithin a single room, a suite of rooms or a small building). Once thecables are placed, the top covers 28 can be installed, awaiting theinstallation of the locking mechanisms to be described below. Wherethere may be prior non-secure raceways of different cross-section usedin the system, one can use raceway covers with modified snap-inconnectors configured to connect to the upper parts of those racewaysand provide the needed security.

A critical element of the present invention is the securing lockingmechanism used to maintain the integrity of the conduit system whilepermitting its simple and easy unlocking and disassembly when desired,while yet insuring that the locking system cannot be unlocked ordisabled by unauthorized means. This is accomplished by means of lockingplate assemblies inserted at the gaps in the top cover installationsalong the conduit. The top cover mechanism and its installation andoperation is best illustrated in FIGS. 3–5, 8–9 and 12–14. (Theembodiment illustrated is typical when the components are made ofaluminum; FIG. 15 parallels FIG. 13 to briefly illustrate the typicalshape differences when the components are made of steel. The minordifferences imparted by different materials of construction arediscussed further elsewhere herein.) One embodiment of the lockingdevice 52 is shown from above and below in FIGS. 4 and 5, respectively.(Other embodiments will be exemplified below.) It comprises a base plate54 which has a lateral width W slightly greater than the width of theopening 30 in the raceway 26. The plate 54 also has an aperture 68 andguides 70 (conveniently formed by bending inwardly two tabs formed bycutting aperture 66) in which a longitudinally extending rod 72 ismounted through holes 76. Aperture 68 is positioned such that retractingrod 72 clears its distal end 84 from being beneath aperture 68. Rod 72has a flange 74 serving as a stop and a hole 78 near one end to which isattached a pull wire 80. A compression spring 82 surrounds the rod 72and its end distal from the hole 78 is attached to the rod 72. Thespring 82 should be of a strength such that when released fromcompression it readily urges the rod 72 into a locked position asdescribed below, but not so strong that an excessive pull on pull wire80 must be used to retract it and release locking top cover 84 whenaccess to the interior of the conduit system is desired. Depending fromthe corners of the plate 54 are U-shaped support brackets 56 withapertures 58 therethrough to guide and support locking pins 60. Wedgedbetween the pair of support brackets 56 at each end of the plate 54 is aspring metal strip 62, preferably made of spring steel. Prior toinsertion into the conduit, the strips 62 are compressed inwardly asshown in FIG. 12 and held in that position by pliers handled by theinstaller. The strips 62 are positioned inwardly of and in contact withflanges 64 on the pins 60. (Other embodiments of securing means will beexemplified below.)

The assembly procedure then continues with the installer loweringlocking device 52 into an opening 30 in the space left between twoclosed top covers 30 (FIG. 12) until the base plate 54 rests on the topflanges 34 of the raceway (FIG. 13). The holes 58 in the brackets 56 arenow disposed below the ribs 36. The installer then releases the springmetal strips 62 which spring outward in contact with the pin flanges 64,thus moving the pins 60 outwardly and under the ribs 36, thus securingthe locking device 52 in place. In each system at least one (and usuallymost or all) pull wire 80 must be long enough so that it extends to andthrough aperture 24 in the side of enclosure 6, where it terminates inpull ring 92. Only pull wires 80 which terminate inside a secureenclosure 6 can be operated to initiate opening the system. Then alocking top cover 84 (FIG. 8) is placed over the opening 30 and thelocking device 52, so that the ends of the locking top cover 84 overlaponto the ends of the two adjacent closed top covers 28 as shown in FIG.3, so that the entire length of openings 30 in the raceways 26 is nowcovered. The locking top cover 84 is placed so that its aperture 88 isaligned with aperture 68 in base plate 54, rod 72 is retracted by aninstaller pulling on pull ring 92 from within the secure enclosure 6,and a T-shaped locking bracket 86 is inserted through apertures 68 and88 so that the leg of the bracket 86 with hole 90 projects into theinterior of the raceway 26 and hole 90 is aligned with the distal end 74of rod 72 (FIG. 3). The pull ring 92 is then released and, impelled bycompression spring 82, rod 72 is urged forward and its distal end 74passes through hole 90 in bracket 86, thus locking bracket 86 fromupward movement and securing locking top cover 84 in place. Allcomponents of the secure conduit system 2 are now interlocked intoposition with each other and none can be moved or removed until rod 82is again retracted from hole 90 in bracket 86 by manipulation of thepull ring 92 from within the secure enclosure 6. With all of the lockingplate assemblies in place and their covers locked to them, the conduitassembly is complete.

Alternative structures are contemplated for the locking device 52 andfor manipulation of the locking and unlocking mechanism. FIG. 21illustrates mechanized variations of the pull wire 80 and manual pullring 92. The housing 182 is contemplated to contain a conventionalmechanical or electromechanical actuator, (not shown) such as a servomechanism, that will reciprocate a linkage 180 which causes the rod 72to engage or disengage the bracket 86 as described above. Alternativelywithin the housing 182 could be a pneumatic or hydraulic actuatorcooperating with linkage 180 (in this case in the form of a fluid-filledtube, which acts through a pressure-to-mechanical coupler 184 to engageor disengage the bracket 86 as described. Housing 182 will also containmeans, preferably activatable from outside the housing, to start theactuator. The source of electrical, pneumatic or hydraulic power to movethe actuator may be internal or external to the housing but should beinternal to the secure enclosure 6. Batteries or pressurized reservoirsof gas or liquid may be maintained within the enclosure 6. If the sourceof the electricity, gas or liquid is outside the enclosure 6, then itmust be provided access to the enclosure 6 in a secure manner consistentwith the overall security of the enclosure and the conduit system.

Further, the locking device 52 may alternatively be mounted as shown forcomparable device 186 in FIG. 22, with the device 186 having a flatconfiguration with mounting bolts 188 the ends of which engagerespectively flanges 34 and ribs 36 and which are thereafter tightenedto secure the device 186 in place. In a further alternative illustratedin FIG. 23, the locking device 52 (here identified as 52′) has slantedlegs 192 projecting downwardly from the base plate 54 and terminating inhooked portions 194. When the device 52′ is inserted into the opening 30of raceway 26, the base plate 54 is seated against the top of raceway 26as described above. However, in this embodiment the legs 192, which areslightly flexible, are forced into contact with the ribs 36 and eachprojecting hooked portion 194 flexes to slide below the underside of arib 36 and then resiles to snap outwardly into locking engagement withthe underside of the rib 34, thus securing the device 52′ in placewithout the need for cooperating pins 60 or springs 62. In anotheralternative shown in FIGS. 24–26, device 52 (identified as 52″) hasrigid straight legs 196 with holes 198. When the bracket 52″ is seatedon the raceway 26, the legs 196 project through the opening 30 and theholes 198 are aligned with the underside of ribs 34. Spring pins 200,which are generally U-shaped devices with angled pin projection 202 arethe ends of the legs of the U-shape, are then flexed closed (asillustrated in FIG. 25) and positioned manually to align the ends ofprojections 202 with the holes 198. Each spring pin 200 is then allowedto resile open allowing the projections 202 to pass through the holes198 (as illustrated in FIG. 26) and engage the undersides of ribs 34 andlock the device 52″ in place. This configuration can be readily unlockedby manually compressing the spring pins 200 to withdraw the projections202 from the holes 198, thus releasing the locking device 52″.

The system can have many other alternative embodiments which will beevident to the person skilled in the art. In FIGS. 33—35 an alternativelocking device 238 is shown, which as compared to locking device 52 isconfigured to simply be seated over the folded top 34′ of flanges 34 ofthe raceway 26. The curved or bent shape of spring pins 200′, ascompared to pins 200, facilitates their being locked in place when theconduits are closed since the contact with the underside of the covers84 urges the pins 200′ down against the base plate 54′. The top 28 hason the underside a U-shaped bracket 241 which has a lateral slot 243through mechanism 238 is placed in the raceway 26 and the top cover 28placed over it, the tab 245 with hole 70′ therein fits into the slot243. When the lanyard or pull cord 80 is pulled to release the rod 72′,spring 82 urges the rod 72′ forward through hole 70′ and tab 245 andbracket 241 are locked together. The rod 72′ is has a pointed end 246 tofacilitate alignment of the rod in its guide holes 70 and 70′. Oncelocked with rod 72′ and with tab 245 seated in slot 243, the section ofthe conduit is locked against motion in all three axes. The lanyard orpull wire 80 can be extended for multiple lengths such as 80′ and 80″ byuse of connectors 184. FIGS. 37–40 illustrate two versions of a multiplelocking embodiment for elbow (L) sections and intersection (T, X and Y)sections, in which there are lanyard or spring pins-operated lockingmechanisms in more than one, and preferably all, of the branches of amultipath section. The enhances the security of the system, as no onecan release the cover 28 of a section by manipulating only one lanyardor pull wire 80 or one spring pin device 200 or 200′. If lanyards areused they can be made long enough to reach to the nearest secureenclosures 6 of the system if desired. Preferably however they willreach only into the next section (as shown in phantom as 26′ in FIG.40), as do the spring pin devices 200′ (FIG. 41). The multipath sectiontherefore cannot be opened until the adjacent sections have been openedand the lanyards 80 or spring pin devices 200′ for the L, T, X or Ysection are accessed. The other sections in turn cannot be opened untilthe initial section is opened by manipulation of a lanyard or pull wire80 which extends into a secure enclosure 6 as described above.

It will therefore be seen that this system is entirely secure fromoutside access or penetration, since it cannot be unlocked other than byrelease from within a secure enclosure, and the secure enclosure itselfcan be opened only by authorized persons. There are no external pointsof entry where an intruder can gain access. All covers are locked to theraceways either the snap-in connectors or by the locking plateassemblies. Any attempt to enter the secure enclosure or the secureconduit is visible to observers, particularly on those segments of thesystem where the raceways are mounted on standoffs from the underlyingsupporting wall or other structure. If it is desired to reenter theconduit, as for instance to lay additional cables or pipes through theconduit, or gain access to a faulty cable or pipe, one can only initiateaccess through a secure enclosure. In a manually operated embodiment, auser will pull on one of the access cables attached to a locking rod ina locking plate assembly to retract the rod and coil spring, removingthe rod from the aperture in the lock plate connector. That section ofthe raceway cover can now be lifted out, exposing the locking plateassembly for removal be releasing the side pins from under the racewayinternal ribs. The interior of the raceway is then entirely open and thecables, pipes, etc. within can readily be accessed. (The removal stepsfor removal of the released locking plate will depend on the structureof each embodiment of the locking plate, as will be evident to thoseskilled in the art from the descriptions of exemplary embodimentsherein. Essentially unlocking and removal steps are merely the reverseof the assembly and locking steps.)

In addition to the obvious security provided to the cables, pipes, etc.,the present invention also eliminates the time-consuming, tedious andoften quite difficult process of “fishing” a cable, wire, etc. through asecure conduit. One can now simply lay the cable, etc. directly into theopen raceway and then securely close the raceway over it with the coversand locking devices. This advantage is particular notable for pipes andother relatively rigid tubes which cannot usually be fished withoutextreme difficulty, and often cannot be fished at all. Such rigiddevices can now simply be laid into the conduits and readily accessedand removed when required.

The materials from which the raceways, top covers and other portions ofthe system will be made will usually be a matter of choice, guided byany specifications defined by the environment or use of the system. Forinstance, NSTISSI 7003 defines materials which are required to be usedin PDS systems, such as steel. NSTISSI 7003 does, however, alsorecognize Simple Distribution Systems (SDS) as a subset of PDS, forwhich broader ranges of materials are acceptable. Further, for thosesystems for which neither PDS nor SDS standards are applicable, thechoice of materials can be based on the user's determination of whatmaterials are appropriate for the system of interest. Therefore, withinany limits defined by applicable published specifications such asNSTISSI 7003, it is anticipated that most components, such as raceways,top covers, and locking mechanisms will normally be formed from metal,especially steel or heavy gauge aluminum, although other non-ferrousmetals such as zinc or brass as well as various specialty ferrous ornon-ferrous alloys may also be used. Woods, ceramics or variousplastics, particularly those known as engineering plastics, or any othermaterial which meets local security requirements may also be used.Spring metal plates will be a springy material, normally a spring steel.The pull wire or halyard for manual or mechanical operation may be metalwire or a strong ceramic fiber or glass fiber or polymeric strandmaterial, or may be a rigid rod of metal or fiber. Ordinary cord such ascotton or organic fiber cord is preferably avoided because of its lowstrength and potential for deterioration. Where the release mechanism ispneumatically or hydraulically operated appropriate fluid tubing will beused. It is preferred that the locking devices be positioned relativelyclose to their adjacent secure enclosures 6 such that pull wires orfluid tubes may be kept to a reasonably short length (e.g., about 1–3feet [30–100 cm]). This will facilitate operation of the releasemechanisms and avoid problems such as kinking in the pull wire or tube.Also preferably the pull wire or tube should not extend around a bend inthe system 2, especially a sharp bend, but if such is necessary it isuseful to have a guide (not shown) at the interior of the bend to guidethe wire or tube around the bend and minimize movement friction and toavoid creating sharp bends and perhaps kinks in the wire or tube.

It will be evident that there are numerous embodiments of the presentinvention which are not expressly described above but which are clearlywithin the scope and spirit of the present invention. Therefore, theabove description is intended to be exemplary only, and the actual scopeof the invention is to be determined from the appended claims.

1. A method, comprising: selecting a first elongated channel member withat least two open ends; placing an elongated carrier in the firstchannel member so that it extends through the at least two open ends;placing a first cover over an open side of the first channel member toform a hollow first conduit section in combination therewith so that theelongated carrier extends therethrough; and locking the first cover tothe first channel member with a locking device that is operable onlyfrom within the first conduit section and is accessible only through anopen end thereof.
 2. A method according to claim 1, further comprising:joining a second channel member and a second cover to form a hollowsecond conduit section; and abutting the second conduit section to anend of the first conduit section to form an elongated conduit; whereinlocking the first cover to the first channel member locks together thesecond cover to the second channel member such that the elongatedconduit can be disassembled only by release of the locking device byaccess through an open end of the elongated conduit.
 3. A methodaccording to claim 2, further comprising: joining a plurality of furthersecond conduit sections into the elongated conduit such that all conduitsections are locked together by the locking of the first cover to thefirst channel member.
 4. A method according to claim 1, wherein placingan elongated carrier in the first channel member comprises: placing oneor more of electrical wiring, optical fiber, and gas or liquidconveyance tubing, in the first channel member.